1. Field of the Invention
The present invention relates to a loading and unloading device for sheet metals and relates, more particularly, to a loading and unloading device for sheet metals for automatically loading and unloading sheet metals to and from a sheet metal working machine.
2. Description of the Related Art
As a related art, there exists a sheet metals loading and unloading device for loading sheet metals to be worked to and unloading worked sheet metals from a turret punch press respectively, for example, as a sheet metal working machine.
This loading and unloading device for sheet metals includes a vacuum chucking unit for lifting a sheet metal by vacuum-chucking the sheet metal corresponding to a position of a movable table of a turret punch press, a loading unit for moving the vacuum chucking unit which has vacuum-chucked the sheet metal to the turret punch press, and an unloader for carrying worked sheet metal from the turret punch press.
At a lower side of the vacuum chucking unit, a pallet for a sheet metal to be worked loaded with a sheet metal to be worked is set, and a pallet for a worked sheet metal for loading a worked sheet metal is mounted on a lifter at a lower side of this vacuum chucking unit.
A supporting table is provided at a height position almost at the same height position as the movable table which is at a lower position of the vacuum chucking unit. This supporting table is capable of freely moving in both lateral directions from a lateral position of the movable table. Particularly, the supporting table can move in a direction orthogonal with a direction of loading and unloading a sheet metal to be worked to and from the turret punch press.
Based on the above-described structure, the vacuum chucking unit lifts a sheet metal loaded on the pallet for a sheet metal to be worked, in the state that the supporting table is moved back to a neutral position for loading and unloading a sheet metal to be worked from the turret punch press. The supporting table is returned to the neutral position to support the vacuum-chucked sheet metal, and the vacuum-chucked sheet metal is carried to the turret punch press by the loading unit.
Further, a worked sheet metal W is carried to the unloader and then the worked sheet metal W is unclamped and loaded on the supporting table. The supporting table is moved back again to move the worked sheet metal. The worked sheet metal is clamped by supporting clampers, the supporting table is advanced, and then the worked sheet metals are separated into individual worked sheet metals by a separation hammer. The separated individual worked sheet metals are dropped and loaded on the pallet for worked sheet metals.
According to the above-described relevant art, however, there is a problem that the loading unit itself has an increased weight which results in a high cost. Further, since the positions for carrying out the vacuum chucking of a sheet metal and the position for loading the sheet metal are the same, there is a problem that the sheet metal working machine has to stop its operation during a period while a next sheet metal is being vacuum-chucked after one sheet metal has been loaded to the sheet metal working machine, in order to avoid an interruption of the sheet metal being worked with the vacuum chucking unit.
Further, when the sheet metal working machine is to be used as a single unit, there is a problem that either the loading unit for sheet metals must be moved or the work must be done from an unnatural position.